抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

4.2.8. Reductive Coupling 3109 5. Reaction of Aromatic Compounds 3110 5.1. Electrophilic Substitutions 3110 5.2. Radical Substitution 3111 5.3. Oxidative Coupling 3111 5.4. Photochemical Reactions 3111 6. Reaction of Carbonyl Compounds 3111 6.1. Nucleophilic Additions 3111 6.1.1. Allylation 3111 6.1.2. Propargylation 3120 6.1.3. Benzylation 3121 6.1.4. Arylation/Vinylation 3121 6.1.5. Alkynylation 3121 6.1.6. Alkylation 3121 6.1.7. Reformatsky-Type Reaction 3122 6.1.8. Direct Aldol Reaction 3122 6.1.9. Mukaiyama Aldol Reaction 3124 6.1.10. Hydrogen Cyanide Addition 3125 6.2. Pinacol Coupling 3126 6.3. Wittig Reactions 3126 7. Reaction of R,â-Unsaturated Carbonyl Compounds 3127

Organic Reactions in Aqueous Media with a Focus on Carbon−Carbon Bond Formations: A Decade Update

The αβ tubulin heterodimer is the structural subunit of microtubules, which are cytoskeletal elements that are essential for intracellular transport and cell division in all eukaryotes. Each tubulin monomer binds a guanine nucleotide, which is non-exchangeable when it is bound in the α subunit, or N site, and exchangeable when bound in the β subunit, or E site. The α- and β-tubulins share 40% amino-acid sequence identity, both exist in several isotype forms, and both undergo a variety of post-translational modifications1. Limited sequence homology has been found with the proteins FtsZ2 and Misato3, which are involved in cell division in bacteria and Drosophila, respectively. Here we present an atomic model of the αβ tubulin dimer fitted to a 3.7-A density map obtained by electron crystallography of zinc-induced tubulin sheets. The structures of α- and β-tubulin are basically identical: each monomer is formed by a core of two β-sheets surrounded by α-helices. The monomer structure is very compact, but can be divided into three functional domains: the amino-terminal domain containing the nucleotide-binding region, an intermediate domain containing the Taxol-binding site, and the carboxy-terminal domain, which probably constitutes the binding surface for motor proteins.

Structure of the alpha beta tubulin dimer by electron crystallography.

6.4. Polyynes 3123 6.5. Using R-Hydroxy Stannanes 3124 6.6. Using the Hurtley Reaction 3124 6.7. Using a Methylenation Reaction 3125 7. Conclusions and Future Prospects 3125 8. Uncommon Abbreviations 3125 9. Acknowledgments 3125 10. Note Added in Proof 3125 11. References 3126 * Authorstowhomcorrespondenceshouldbeaddressed(evano@chimie.uvsq.fr, nicolas.blanchard@uha.fr). † Université de Versailles Saint Quentin en Yvelines. ‡ Université de Haute-Alsace. Chem. Rev. 2008, 108, 3054–3131 3054

Copper-mediated coupling reactions and their applications in natural products and designed biomolecules synthesis.

Alkaloids and phenolics of Wurmbea and Burchardia species

Structures de l'odyendane et l'odyendene deux nouveaux quassinoides d'odyendea gabonensis (pierre) engl. Simaroubacees.

Taxoids: 11,12-dihydro-4-deacetyldocetaxel

Publisher Summary This chapter presents metabolism and pharmacology of taxoids. Three main modifications occur in taxoids when they are introduced in the organism—namely, (1) epimerization, (2) hydrolysis, and (3) hydroxylation. After 72 h of incubation, the ratio of 7-epi-paclitaxel to paclitaxel varies from 0.36 to 0.48 in the cell and from 0.25 to 0.32 in the medium, depending on the cell line and on the initial concentration of paclitaxel. The epimerization of paclitaxel occurs in the medium in the presence or absence of cells. The reversible epimerization of the hydroxyl group at C-7 occurs with both paclitaxel and docetaxel. Two derivatives resulting from the hydrolysis of paclitaxel have been observed in human patients. Cleavage of the side chain at C-13 of the taxane ring results in the formation of baccatin III, while 10-deacetyl paclitaxel results from the cleavage of the acetyl group at the C-10 of the taxane ring. Hydroxylation is pharmacologically important, since hydroxylated compounds are the major metabolites of paclitaxel and docetaxel, leading in all cases to less cytotoxic derivatives which are readily eliminated.

4 Metabolism and pharmacology of taxoids

Étude de réactions photochimiques—XXIV: Réactions intramoléculaires de type ionique des alcools allyliques et homo-allyliques: Une approche vers l'étude conformationnelle des cholestènes-4 et cholestènes-5 excités☆

Daniel Guenard

Papers

Alkaloids and phenolics of Wurmbea and Burchardia species

Structures de l'odyendane et l'odyendene deux nouveaux quassinoides d'odyendea gabonensis (pierre) engl. Simaroubacees.

Taxoids: 11,12-dihydro-4-deacetyldocetaxel

4 Metabolism and pharmacology of taxoids

Étude de réactions photochimiques—XXIV: Réactions intramoléculaires de type ionique des alcools allyliques et homo-allyliques: Une approche vers l'étude conformationnelle des cholestènes-4 et cholestènes-5 excités☆